Mounting for sewing-machine motors



June 1 632 781 21 1927 w. BANGSER MOUNTING FOR SEWING MACHINE MOTORSFiled Dec. 10, 1925 Sheets-Sheet 1 3 INVEN OR m 0m 5 WZQ,

M ATTORNEY 1, 2, June 21,1927. w. BANGSER 3 781 MOUNTING FOR. sswmemomma MOTORS d Filed Dec; 10. 1925 2 Sheets-Sheet 2 5 1 6 i 6' gg: X I

Patented June 21, 1927.

UNITED STATES PATENT OFFICE.

WILLIAM BANGSER, OE NEW YORK, N. Y., ASSIGNOR 'IO MAIMIN SIEED CONTROLCORPORATION, A CORPORATION OF NEW YORK.

MOUNTING FOR SEWING-MACHINE MOTORS.

This invention relates to motor drives for sewing machines and moreparticularly to means for mounting the motor in driving relation to themachine.

It is common practice to drive sewing 1na chines by means of smallelectric motors externally mounted adjacent the hand-wheel of themachine, driving either through frictional contact with the periphery ofthe hand-wheel or by means of a belt. Such drives when used inconnection with commercial machines can be bolted to the table orotherwise permanently fixed in position; the problem of providing amounting for the drive on a domestic sewing machine is not so simple.Such a mounting should be readily secured to all types of hand orfootoperated domestic sewing machines without the use of screws, boltsor other fastening means requiring the services of a mechanic anddefacing the machine or its stand. It should be readily removable topermit clos ing or covering of the machine and yet hold the motorsecurely in position during use. It is an object of the presentinvention to provide such a mounting, particularly adapted for use inconnection with domestic machines.

The speed of the sewing machine must be under control, and this controlis commonly effected by varying the speed of the motor by means of arheostat. The use of rheostats is objectionable for several reasons;they are expensive, they get out of order easily, and they do not, forthe most part, give a smooth curve variationin the speed of the motor. Iprefer to vary the speed of the machine, not by varying the speed of themotor held in fixed driving relation to the machine, but by varying thedriving pressure between the motor and the machine while running themotor at constant speed. This variation in the driving pressure iseffected by a controlled bodily movement of the motor relative to themachine. When the drive is a friction drive, the functional contactbetween the driving pulley of the motor and the hand-wheel of themachine is varied, and where the drive is a belt drive, the tension onthe belt is varied. In order to limit the maximum driving pressure ithas been proposed to en'iploy the weight of the motor itself forexerting this pressure. This is com monly known as the gravity controland is illustrated in Patent No. 1,377,018 wherein is described a motordrive for sewing machines in which a motor running continuously at aconstant speed is mounted adjacent the machine and constantly agged intodriving relation by means of. its own weight. This movement, however, isopposed by means of a spring which normally holds the motor ininoperative position and the force of which must be counteracted by theoperator to permit the motor to move under its own weight into drivingposition. The effective driving pressure of the motor and hence thespeed I of the sewing machine can thus be nicely.

and easily controlled. It is a more specific ob ect of the presentinvention to provide a motor mounting suitable for a drive inwhich thespeed of the machine is varied by varying the driving pressure of themotor, and particularly adapted for a gravity control drive.

In attaining these objects I have mounted the motor upon a supportintended to rest upon the table or stand of the machine and clamped inposition between the table and the frame of the machine by means of anarm extending from the support and bearmounted adjacent the hand-wheelin accordance with the present invention, Figure 2 is a section takenalong line 2--2 of Figure 1. Figure 3 is a section taken along line 33of Figure 1, and Figure 4 is a plan View of the motor support and motor.The sewing machine illustrated in these figures comprises the usualframe 1 extending upward from a horizontal surface or table 2, andhaving a hand-wheel 3, the shaft of which is journaled within a boss 1eXtending-fearwardly from and forming an integral part of the frame. Ishall now describe the motor drive and its mounting.

Resting upon the table to the right of the frame and beneath the handwheel is a motor-supporting base member on which is pivotally mounted at6 a bracket 7 provided with a yoke 8 on which, 1n turn, the motor 9 ispivotally' mounted at 10 in such a manner that the cone-shaped drivingpulley 11 of the motor is positioned immediately below the handwheel 8.The shaft of the motor is in a plane with the axis of rotation of thehandwheel and generally parallel thereto. The motor support is clampedin position on the table by means of a vertical arm 13 adjust-- ablymounted on the bracket 7 and provided at its upper end with a yoke 14which bears a ainst the lower side of the boss 4:. The ah'm 12 is heldin vertical adjustment by means of a set screw 15. It will be observedthat the center of .gravity of the motor is well beyond the pivot-"point6 on the far side of the frame so that the moment exerted by the weightof the motor about the point 6 tends to hold the yoke 14- firmly againsta the boss 1.- Thus, although the motor support can be clamped betweenthe frame and the table by means of manual adjustment of the arm 13,fixed by set screw 14, a tight contact between the arm and the boss, andbe 'tween the base and table is always assured because of this momentexerted by the weight of the motor about the point 6. I shall nowdescribe briefly the manner in which the gravity speed control principleis adapted to the motor drive of the present invention.

Secured to the lower part of the motor housing is a cylindrical casing16 which houses a compression coil spring 17 and acylindrical shell 18.The inner end of this coil spring bears against a cap 19 on the casingand the outer end against the bottom of the shell 18, which. in turnbears against the bracket 7. The spring is so designed that, pressingagainst the fixed bracket 7 through the end of the shell 18, it opposesthe weight of the motor and normally holds it tilted about its pivot inthe position illustrated in full lines in the drawing, the drivingpulley being thus held out of contact with the handwheel as shown. Inorder to permit the motor to swing downward about its pivot and move thedriving pulley into cogitact with the hand-wheel it is necessary tocompress the spring. This is done by means of a Bowden wire 21 under thecontrol of the operator. This Bowden wire comprises the usual casing 22and inner wire 23. The upper end of the wire23 is secured to the bottomof the shell18 and the lower end to a treadl'e 24; The operator bypressing the outer end of the treadle downward exerts a pull on the wire23 which, acting through the shell 18, compresses the spring 17, thusovercoming theeffectiveness of that springand permitting the motor toswing its driving pulley into contact with the hand-wheel.

With the spring casing.

The driving pressure exerted by the driving pulley against thehand-wheel can thus be controlled by the operator and the speed of isone of true tangency. As the pressure increases this contact may developinto a small area, but-the increase in the efiective driving pressure isconstant. WVith a grooved pulley this might not be the case. The pulley,shaped and positioned as illustrated, also tends to move the motortoward the machine and hence tighten the clamping action exerted by thesupport and the arm 13. I

The spring casing 16 is adjustably mountedv on the motor housing bymeans of a pair of set screws extending through longitudinal slots 26ina plate 27 aflixed to or integral By adjusting the position of thecasing relative to the motor the normal angular elevation of the lattercan be controlled and the drive thus made comformable to hand'wheels ofdifferent dimits of all of the fine adjustments inher ent in thegravitycontrol principle. The mounting'of the present invention is quickly andeasily placed inposition and just as easily and quickly removed. Anyhousewife can readily do these things and readily operate the drive whenin position. Furthermore, there is nothing about the mounting requiringthe use of any permanent fixture on the sewing machine and nothing whichcan in any way mar or scratch it.

I claim:

1. In a sewing machine having a frame and a table, the combination ofmotor-supporting base resting on the table adjacent the frame, a bracketpivotally mounted on the base, a motor mounted on the bracket with itscenter of gravity beyond the pivot on the far side of the frame, andmeans extending from the bracket and bearing against the frame forclamping the base between the frame and the table. j

j. 2. In a sewing machine having a table, a

- frame and a boss on the frame, the combinathe hand-wheel shaft isjournaled, and a table, the combination of a support for a motor restingon the table, a motor on the support, a driving pulley on the motorcontacting with the hand-wheel, and a vertical arm extending upward fromthe support and bearing against the boss.

a. In a sewing machine having a handwheel, a frame and a table, thecombination of a support for a motor resting on the table,

a motor pivotally mounted on the support with its axis generallyparallel with the axis of rotation of the hand-wheel, a driving pulleyon the motor positioned below the hand-wheel and urged into contacttherewith by the weight of the motor, means for clamping the supportbetween the table and the frame, a spring opposing the weight of themotor and normally holding the driving pulley out of contact with thehand-wheel, and means under the control of the operator forcounteracting the force of the spring and per nitting the weight of themotor to move the driving pulley into driving contact with thehand-wheel.

5. In a sewing machine having a table, a frame and'boss on the frame,the combination of a motor base resting on the table, a supportingbracket pivotally mounted on the base, a motor mounted on the bracketwith its center of gravity beyond the base pivot on the far side of theframe, an arm mounted on the bracket and contacting with the boss, andmeans for moving the motor into and out of driving relation to themachine.

6. A motor drive for a sewing machine having a frame, a hand-wheel and atable, comprising the combination of a motor, a driving pulley on themotor, a support for the motor, means for clamping the su port betweenthe frame and the table with the driving pulley adjacent the hand-wheeland constantly urged into contact therewith by the weight of the motor,a spring carried by the motor normally opposing the weight of the motorand holding the driving pulley out of contact with the hand-wheel andmeans frame and the table, a motor pivotally mounted on the supportbeyond and below the hand-wheel about an axis transverse to its own axisof rotation, the axis of rotation of the motor being in a vertical planewith the axis of rotation of the hand-wheel, and a frustro-conicaldriving pulley on the motor positioned to contact with the handwheel thelarge end oi the pulley being be tween the point of contact and theframe of the machine.

8. A motor drive for a sewing machine having a frame, a haud wheel and atable, comprising the combination of a motor, a driving pulley on themotor, a support for the motor holding the driving pulley adjacent thehand-wheel and constantly urged into contact therewith by the weight ofthe motor, a spung carried by the motor normally opposing the weight ofthe motor and holding the driving pulley out of contact with thehand-wheel and means under the control of the operator for counteractingthe eflfect of the spring.

9. A motor drive for a sewing machine having a frame, a hand-wheel and atable, comprising the combination of a motor, a driving pulley on themotor, a support for the motor holding the driving pulley ad-l jacentthehand-wheel and constantly urged into contact therewith by the weight ofthe motor, a spring carried by the motor abutting against a fixedelement normally opposing the weight of the motor and holding thedriving pulley out of contact with the hand-wheel, means permittingadjustment of the spring relative to the motor, and means under thecontrol of the operator for counteracting the GIIQClJ of the spring.

In testimony'whereot I aflix my signature.

WILLIAM BANGSER.

